This tool allows you to animate 2D sprite in ECS with Vat technique.
Tutorial Video: https://youtu.be/YPocvxhJV24
OPTIONAL: You can use "Sprite to Mesh" for improving ECS performance. With this way you almost achieve 2x FPS performance because Unity's built-in ECS SpriteRenderer is very poor right now.
Inspired from: https://github.com/fuqunaga/VatBaker